As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU MAKES BEARING WHINE NOISE. OIL SMELL IN CABIN. SHUT IT DOWN AT GATE. TOMC CONTACTED, APU CONSIDERED INOPERATIVE FOR FURTHER T-S. INF- :WORK WITH LM5169. INF- :REMOVED APU PER MM. APU HRS READS=18743 AND CYCLE COUNTER READS=15277. RPLC'D APU.